[Results of treatment of a distal deep bite according to the cephalometric analysis].

Aim of the research is analyze of changes of facial cranium bones morphometric parameters as a result of distal overbite orthodontic care. On the basis of examination of 214 head telerentgenogramms in lateral projections which where received before and after orthodontic care, facial cranium bones sizes where defined, that changed as overbite orthodontic treatment result with the account of main direction of bones' development. Analyzing angular linear sizes and their correlation in case of distal overbite, there were observed teeth position disorder, alveolar arches, jaw-bones and their characteristic sizes. Among patients with mixed overbite in the period of jaw-bones active grow the treatment was based on 2 phases - 1) earl orthodontic therapy with the use of "2*4" system with labial bumper in space of lower bone, 2) final phase was held with the help of straight wire technique. In the period of second teeth simultaneously with straight wire technique we used occlusive brackets fixed on upper incisor teeth palatal surface: among 28 patients we have fixed lingual brackets of "Ormco" production on upper incisors, among 79 patients we have stuck composite occlusive plates, intermandibular draft was used, which sponsored upper lower jaw-bones lateral teeth alveolar prolongation. While comparing results with deep distal overbite before and after orthodontic care, we were able to find out statistically guaranteed differences in following sizes; incisor overbite depth and sagittal fissure size, which corresponded to the norm after care. In the process of care advantageous alveolar compensation was fixed; facial esthetic and jaw-bones position was changing for the better. In case of horizontal and neutral types of jaw-bones growth the correction of incisor overbite depth happens on the account of alveolar height reduction in space of upper and lower jaw-bones incisors and that parameter increase in space of both jaw-bones lateral teeth. In case of vertical type of jaw growth alveolar shortening in space of upper jaw-bone was observed and in a less degree- of upper and lower jaw lateral teeth, and, also, of lower jaw incisors. Before and after orthodontic treatment the previous type of growth remained the same.

Electrostatic effects in macromolecules: fundamental concepts and practical modeling.

The past few years have seen an exponential growth in the calculations of electrostatic energies of macromolecules and an increased recognition of the crucial role of electrostatic effects. This review considers the current state of the field. Focus is placed on calculations of pKas, redox potentials and binding energies in macromolecules and clarification of the fact that the value of the dielectric 'constant' of a protein depends on its definition and that small dielectric constants should not be used in describing charge-charge interactions by current continuum models.

Energy considerations show that low-barrier hydrogen bonds do not offer a catalytic advantage over ordinary hydrogen bonds.

Low-barrier hydrogen bonds have recently been proposed as a major factor in enzyme catalysis. Here we evaluate the feasibility of transition state (TS) stabilization by low-barrier hydrogen bonds in enzymes. Our analysis focuses on the facts that (i) a low-barrier hydrogen bond is less stable than a regular hydrogen bond in water, (ii) TSs are more stable in the enzyme active sites than in water, and (iii) a nonpolar active site would destabilize the TS relative to its energy in water. Combining these points and other experimental and theoretical facts in a physically consistent frame-work shows that a low-barrier hydrogen bond cannot stabilize the TS more than an ordinary hydrogen bond. The reason for the large catalytic effect of active site hydrogen bonds is that their formation entails a lower reorganization energy than their solution counterparts, due to the preorganized enzyme environment.